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Biomedical subjects

K Hayasaka

Publications and source records attributed to K Hayasaka.

At least 91 records · Page 5Linked to original sources
PubMed1998

Neonatal hyperbilirubinemia and mutation of the bilirubin uridine diphosphate-glucuronosyltransferase gene: a common missense mutation among Japanese, Koreans and Chinese.

We analyzed the bilirubin uridine diphosphate-glucuronosyltransferase (B-UGT) gene in 42 Japanese newborns with hyperbilirubinemia and determined that 21 infants were heterozygous while 3 was homozygous for Gly71Arg. Allele frequency of Gly71Arg was 0.32 in newborns with hyperbilirubinemia, which was significantly higher than 0.13 in healthy Japanese controls. This mutant allele is also prevalent among Korean and Chinese healthy controls with a frequency of 0.23 in both populations. However, this mutation was not detected in 50 healthy German controls. These data suggest that the high frequency of the Gly71Arg mutation of the B-UGT gene is associated with high incidence of neonatal hyperbilirubinemia in Japanese, Korean and Chinese populations.

Alleles↗
PubMed1998

CD48 expression on leukocytes in infectious diseases: flow cytometric analysis of surface antigen.

BACKGROUND: The function of CD48, one of the pan leukocyte cell surface antigens, is not yet well understood. CD48 was recently shown to enhance the CD40-mediated activating signal to B lymphocytes. As CD48 is one of the activation antigens of monocytes, neutrophils and lymphocytes, a change of its expression on the cells could be expected in infectious diseases. METHODS AND RESULTS: Leukocytes from 27 healthy controls and 97 patients with various infectious diseases were stained with anti CD48 antibody and analyzed by flow cytometry. On monocytes and neutrophils, the CD48 expression was increased in all of the patients with varicella, measles, rubella, infectious mononucleosis, streptococcus tonsillitis, sepsis and appendicitis. On lymphocytes, a significant increase of CD48 was also detected in the patients with the same diseases, except those with sepsis or appendicitis. The normalization of increased CD48 expression was confirmed on monocytes at the convalescent phase. CONCLUSION: These data suggest that CD48 expression on leukocytes reflects the disease activity of infectious diseases, especially of viral infections.

Adolescent↗
PubMed1997

Evolution of a fetal expression pattern via cis changes near the gamma globin gene.

One basis for the evolution of organisms is the acquisition of new temporal and spatial domains of gene expression. Such novel expression domains could be generated either by cis sequence changes that alter the complement of trans-acting regulators binding to control elements or by changes in the expression patterns of one or more of the regulatory (trans) factors themselves. The gamma globin gene is a prime example of a gene that has undergone a distinct change in temporal expression at a defined time in evolution. Approximately 35-55 million years ago, the previously embryonic gamma gene acquired a fetal expression pattern. This change occurred in a simian primate ancestor after the separation of simian and prosimian primates but before the further separation of the major simian lineages; thus, the (prosimian) galago gamma gene retains the ancestral embryonic expression pattern, whereas the (simian) human gamma gene is fetal. This analysis of galago and human gamma genes in transgenic mice demonstrates that cis changes in sequences within a 4.0-kilobase region surrounding the gamma gene were responsible for the evolution of a novel fetal expression pattern in the gamma globin genes of simian primates.

Animals↗
PubMed1997

Balloon pulmonary valvuloplasty for pulmonary valve stenosis with atrial septal defect.

We performed successful balloon pulmonary valvuloplasty (BPV) in 6 patients with pulmonary valve stenosis and atrial septal defect (ASD) accompanied by atrial left-to-right shunt without an increase of shunting immediately after BPV. It suggests that such patients should be treated by BPV initially and the need for ASD repair can be assessed during long-term follow-up.

Catheterization↗
PubMed1997

Right and left ventricular function assessed by regional wall motion analysis in patients with tetralogy of Fallot.

We studied pre- and postoperative regional right and left ventricular wall motion and global ejection fraction in 18 patients with tetralogy of Fallot who had successful repair, and compared these values to those of patients with a history of Kawasaki disease as controls. Right ventricular ejection fraction was significantly lower in the preoperative group (52 +/- 4%) than that in the control group (57 +/- 4%), and that in the postoperative state (49 +/- 4%) was significantly lower than those in the control and preoperative groups. Left ventricular ejection fraction was significantly lower in the preoperative group (56 +/- 7%) than that in the control group (61 +/- 5%), while that in the postoperative state (64 +/- 6%) was significantly higher than those in the control and preoperative groups. Regional ventricular wall motion analysis revealed that shortening fractions in the tricuspid valve region were reduced in the preoperative patients and were persistent even after successful repair; those in the right ventricular outflow tract region were decreased after the correction. Regional left ventricular wall motion showed that shortening fractions in the anterolateral region were improved after the correction. We conclude that right ventricular dysfunction was present in the preoperative patients with tetralogy of Fallot and was persistent even after total correction.

Case-Control Studies↗
PubMed1997

Facilitated diagnosis of CMT1A duplication in chromosome 17p11.2-12: analysis with a CMT1A-REP repeat probe and photostimulated luminescence imaging.

Charcot-Marie-Tooth disease type 1A (CMT1A) is a common autosomal dominant demyelinating peripheral neuropathy. Most patients with CMT1A have been found to have a 1.5 megabase tandem DNA duplication in chromosome 17p11.2-12. Meiotic unequal crossover mediated by the CMT1A-REP repeat is a proposed mechanism for generation of the duplication in CMT1A and a reciprocal deletion seen in hereditary neuropathy with liability to pressure palsies. Testing for the CMT1A duplication is frequently the first step in the molecular diagnosis of patients with suspected inherited demyelinating neuropathy. We used a 1.0 kb EcoRI-PstI DNA fragment (pHK1.0P) from the proximal CMT1A-REP repeat as a probe for Southern blot analysis and detected increased gene dosage in CMT1A by determining measuring radioactivity ratios with a photostimulated luminescence imaging plate. We found that this method is useful for rapid diagnosis of the DNA duplication associated with CMT1A.

Autoradiography↗
PubMed1997

Locations of crossover breakpoints within the CMT1A-REP repeat in Japanese patients with CMT1A and HNPP.

The crossover breakpoints for Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP) are located in the CMT1A-REP repeat flanking a 1.5-Mb region of chromosome 17p11.2-12. The precise locations of the breakpoints are heterogeneous, and we analyzed the relative frequency distribution of breakpoints in 33 unrelated Japanese CMT1A and 3 unrelated HNPP families. The CMT1A-REP repeat region was divided into five regions, A, B, C, D and E, based on restriction site differences between the proximal and distal CMT1A-REP repeats. The frequency distribution of breakpoints within the CMT1A-REP repeat in the Japanese patients was 3% in region A, .78% in B/C and 19% in D, which is similar to that in Caucasian patients. This result also indicates that an 8-kb region defined by region B/C is a recombinational hotspot within the CMT1A-REP repeat in Japanese patients.

Asian People↗
PubMed1997

Chromosomal aberration in lipoblastoma: a case with 46,XX,ins(8;6)(q11.2;q13q27).

Chromosomal aberrations involving 8q11.2 have been reported in lipoblastoma. We report here a case of lipoblastoma with new chromosomal aberration. 46,XX,ins(8;6)(q11.2;q13q27). Cytogenetic analysis would facilitate the clinical differentiation between myxoid liposarcoma and the pathologically similar lipoblastoma and the identification of genetic loci related to cellular growth.

Chromosome Aberrations↗
PubMed1997

Microangiopathic hemolytic anemia and thrombocytopenia in a child with atrial septal defect and pulmonary hypertension.

Microangiopathic hemolytic anemia and thrombocytopenia have been reported in patients with primary pulmonary hypertension, but not in patients with congenital heart disease even if accompanied with pulmonary hypertension. We present a 7-year-old boy with atrial septal defect and pulmonary hypertension who developed microangiopathic hemolysis and thrombocytopenia. Microangiopathic hemolytic anemia and thrombocytopenia should be remarked as a complication in patients with congenital heart disease.

Anemia, Hemolytic↗
PubMed1997

Management of functional pulmonary atresia with isoproterenol in a neonate with Ebstein's anomaly.

Ebstein's anomaly is a rare congenital cardiac anomaly showing significant clinical manifestations with a high mortality rate in the neonatal period. The prognosis of the patient is essentially determined by the severity in morphological changes, however, high pulmonary vascular resistance in the neonatal period may aggravate tricuspid regurgitation and lead to functional pulmonary atresia. We describe a critically ill neonate with morphologically mild Ebstein's anomaly who was successfully managed with intensive care including isoproterenol administration for functional pulmonary atresia. Isoproterenol is a potent pulmonary vasodilator with inotropic and chronotropic effects, and seemed to decrease the pulmonary vascular resistance allowing increased antegrade blood flow to the pulmonary artery and improved cardiac output. If tachycardia is not present, isoproterenol administration is recommended in critically ill neonates with anatomically mild Ebstein's anomaly and no associated cardiac defects.

Ebstein Anomaly↗
PubMed1997

Apolipoprotein E Sendai (arginine 145-->proline): a new variant associated with lipoprotein glomerulopathy.

Lipoprotein glomerulopathy (LPG) is a novel disease characterized by proteinuria, lipoprotein thrombi in the glomeruli, and increased concentration of plasma apolipoprotein (apo) E. It is believed that a genetic disorder of apo E may be present and associated with the disease. Three patients with LPG were examined in this study. The patients' DNA sequences were analyzed, and a nucleotide G to C point mutation in exon 4 of the apo E gene was confirmed in each patient. This missense mutation denotes amino acid substitution of the proline residue for arginine residue at position 145 of apo E. This variant (apo E Sendai) may cause a marked molecular conformational change of the apo E. These findings suggest that a novel variant is etiologically related to LPG.

Aged↗
PubMed1997

Pressure palsy as the initial presentation in a case of late-onset Charcot-Marie-Tooth disease type 1A.

We report siblings of late-onset Charcot-Marie-Tooth disease type 1A (CMT1A) of whom the elder brother presented with drop foot. DNA analysis confirmed the 17p11.2-p12 duplication. Estimation of the age of onset is difficult in CMT1A because of the subtle and slow progress of the symptoms. These cases are unique in that the initial clinical manifestation was a pressure palsy in the brother and both siblings were quite delayed in their clinical presentations. The peripheral myelin protein-22 gene duplication is uniformly found in CMT1A patients. However, other factors influencing the disease manifestations are yet to be determined.

Aged↗
PubMed1997

Defective signal transduction through the thromboxane A2 receptor in a patient with a mild bleeding disorder: deficiency of the inositol 1,4,5-triphosphate formation despite normal G-protein activation.

We describe an 11-year-old girl with a mild bleeding disorder since early childhood. The disorder was characterized by a prolonged bleeding time, and the patient's platelets showed defective aggregation responses to thromboxane A2 (TXA2) mimetic U46619 and arachidonic acid. In contrast, the platelets showed normal responses to thrombin and Ca ionophore A23187. When the platelet TXA2 receptor was examined with the [3H]-labeled TXA2 agonist U46619, the equilibrium dissociation rate constants (kd) and the maximal concentration of binding sites (Bmax) of the patient's platelets were within normal ranges. Normal GTPase activity was also induced in the patient's platelets by stimulation with U46619, however, inositol 1,4,5-triphosphate (IP3) formation was not induced by U46619. These results suggests that the patient's platelets had a defect in phospholipase C activation beyond TXA2 receptors.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1996

New form of platyspondylic lethal chondrodysplasia.

We report on a sporadic case of hitherto unknown lethal skeletal dysplasia. The cardinal clinical manifestations consisted of frontal bossing, cloudy corneae, low nasal ridge, and micrognathia, hypoplastic thorax, and rhizomelic micromelia. Laryngoscopy and neck CT disclosed laryngeal stenosis, and brain CT demonstrated hypoplasia of the corpus callosum. Skeletal survey demonstrated hypoplasia of facial bones and short skull base, extremely severe platyspondyly, hypoplastic ilia, and delayed epiphyseal ossification and rhizomelic shortness of tubular bones. The long bones appeared overtubulated with exaggerated metaphyseal flaring. The humeri were particularly short and bowed. Bowing of the radii and ulnae with subluxation of radial heads presented as a Madelung-like deformity. Unlike the long bones, the short tubular bones were not short and normally modeled. The skeletal changes were superficially similar to those in a group of lethal platyspondylic chondrodysplasias, but were inconsistent with any known subtypes of this group or other lethal skeletal dysplasias.

Abnormalities, Multiple↗